Updating and re-fitting a model

update updates and re-fits a model on the basis of an object of class 'drc'.

Usage

# S3 method for class 'drc'
update(object, ..., evaluate = TRUE)

Arguments

object

an object of class 'drc'.

...

arguments to alter in object.

evaluate

logical. If TRUE model is re-fit; otherwise an unevaluated call is returned.

Value

An object of class 'drc'.

Author

Christian Ritz

Examples

## Fitting a four-parameter Weibull model
model1 <- drm(ryegrass, fct = W1.4())

## Updating 'model1' by fitting a three-parameter Weibull model instead
model2 <- update(model1, fct = W1.3())
anova(model2, model1)
#> 
#> 1st model
#>  fct:      W1.3()
#> 2nd model
#>  fct:      W1.4()
#> 
#> ANOVA table
#> 
#>           ModelDf    RSS Df F value p value
#> 1st model      21 8.9520                   
#> 2nd model      20 6.0242  1  9.7205  0.0054